Which function is a linear function? A. 1 − 3x2 = -y B. y + 7 = 5x C. x3 + 4 = y D. 9(x2 − y) = 3 E. y − x3 = 8

Question

asked Jul 25, 2019 93.3k views

2 Answers

Valentin Shergin · Answer 1 · 2019-07-31T16:01:54+0000

For this case we have that by definition, a linear function is of the form

y = mx + b

We have the following options:

A)
1-3x ^ 2 = -y

Rewriting:

y = 3x ^ 2-1

It's a quadratic function!

B)
y + 7 = 5x

Rewriting:

y = 5x-7

It's a linear function!

C)
x ^ 3 + 4 = y

Rewriting:

y = x ^ 3 + 4

It's a cubic function.

D)
9 (x ^ 2-y) = 3

Rewriting:

$9x ^ 2-9y = 3\\9y = 9x ^ 2-3\\y = x ^ 2- \frac {3} {9}$

It's a quadratic function!

E)
y-x ^ 3 = 8

Rewriting:

y = x ^ 3 + 8

It's a cubic function!

Answer:

The linear function is option B